It is known that ski-lifts constructed for the uphill transportation of skiers in ski resorts comprise inter alia chair-lifts in which the vehicles transporting the passengers, instead of bearing on the ground through wheels, are suspended from a pull and carrier rope supported by grooved rollers rotating on top of towers. Outside this property of "flying" over the generally uneven and snow-clad ground without touching it, the thus propelled chairs do not differ appreciably from conventional vehicles rolling on wheels and accomodating two or three passengers sitting side by side in the free air, without any protection against weather conditions.